Enable OSR optimization for functions with try-catch.

runtime/vm/flow_graph_builder.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/flow_graph_builder.h"
 
 #include "lib/invocation_mirror.h"
 #include "vm/ast_printer.h"
 #include "vm/bit_vector.h"
 #include "vm/class_finalizer.h"
@@ skipping 3923 matching lines @@
       new TargetEntryInstr(AllocateBlockId(),
                            CatchClauseNode::kInvalidTryIndex);
   graph_entry_ = new GraphEntryInstr(parsed_function(), normal_entry, osr_id_);
   EffectGraphVisitor for_effect(this);
   parsed_function()->node_sequence()->Visit(&for_effect);
   AppendFragment(normal_entry, for_effect);
   // Check that the graph is properly terminated.
   ASSERT(!for_effect.is_open());
 
   // When compiling for OSR, use a depth first search to prune instructions
-  // unreachable from the OSR entry.  Catch entries are not (yet) properly
-  // recognized as reachable.
+  // unreachable from the OSR entry. Catch entries are always considered
+  // reachable, even if they become unreachable after OSR.
   if (osr_id_ != Isolate::kNoDeoptId) {
-    if (graph_entry_->SuccessorCount() > 1) {
-      Bailout("try/catch when compiling for OSR");
-    }
     PruneUnreachable();
   }
 
   FlowGraph* graph = new FlowGraph(*this, graph_entry_, last_used_block_id_);
   return graph;
 }
 
 
 void FlowGraphBuilder::PruneUnreachable() {
   ASSERT(osr_id_ != Isolate::kNoDeoptId);
@@ skipping 41 matching lines @@
           LanguageError::kBailout,
           Heap::kNew,
           "FlowGraphBuilder Bailout: %s %s",
           String::Handle(I, function.name()).ToCString(),
           reason));
   I->long_jump_base()->Jump(1, error);
   UNREACHABLE();
 }
 
 }  // namespace dart